Innovative WITRON technology for perishable goods

In the beginning of 2010, Delhaize, the Belgian food retailer, opened a new distribution center for perishable goods in Asse-Zellik near Brussels. The heart of the system is WITRON’s DPS (Dynamic Picking System), an automated storage and picking system. WITRON Logistik + Informatik GmbH, based in Parkstein, Germany, is a turn-key automation supplier, offering design through general contracting. Delhaize has been using WITRON’s DPS in its dry assortment since 2003, so the expansion of this technology to its perishable assortment was a logical next step. With sales revenue of almost 20 billion Euros worldwide, Delhaize is the second largest retailer in Belgium. Some 25% of their turnover is generated in Belgium.

The logistic demands for distributing perishable goods at Delhaize have changed dramatically in recent years. The number of smaller stores and points of sale has increased. Furthermore, delivery frequency to the stores has increased based on a greater emphasis on freshness. For a manual warehouse system, these challenges would mean more handling effort for less product value. Thanks to WITRON’s DPS, Delhaize now has the possibility to fulfill different customer needs quickly and efficiently, with the flexibility to accommodate future changes.

“With this investment, we will be able to pro-actively react to changing market requirements” said Vincent de Hertogh, Manager Supply Chain Strategy, to an audience of 60 logistics managers of the European food retail industry in the course of the WITRON Logistics Day. “The new logistics center plays a central role for the optimization of the entire supply chain within our highly dynamic distribution of perishable goods”.

Project deadlines were strictly keptThe decision to award WITRON the order to act as general contractor for the project “DC Fresh 2” was made in autumn 2007. Delhaize was already starting to use the system in the beginning of 2009, and ramp-up was fully completed after little more than 6 months. All customers could then be supplied with all articles from the new distribution center. “For a project of this magnitude and complexity, this was an extremely challenging time schedule”, emphasizes WITRON project manager Gerhard Krauß. “But based on the common and collaborative partnership between Delhaize and WITRON, we were always on track to insure a successful and timely implementation”, explains Krauß.

Productivity has doubled – costs could be reducedLooking back, many challenges were solved during the course of this project, says de Hertogh. “As a perishable warehouse does only store sensitive products, this project wasn’t only about implementing a new system”, says the Delhaize manager. “In addition to that, we needed to collect more precise master data for our items, and we had to insure that our suppliers could adapt to our new working method. Today, Delhaize receives their goods in storage totes from their suppliers instead of in cartons or other carriers as they had before. The hard work and the investment have paid off. The productivity in the new warehouse has more than doubled compared to the previous working method, and the pool costs for the perishable good totes decreased considerably. Picking errors are nearly eliminated. Also, energy consumption has been reduced significantly. “Despite mechanization, it is 50% lower than in a conventional warehouse”, explains de Hertogh. Although a lot of progress has already been made, the Delhaize manager sees additional optimization potential in the future based on the flexibility of the new DPS system.

Tracking & tracing thanks to jointly developed totesWhile the manual system was using 13 different tote types for order picking, today only two different types are used. These totes were developed by both Delhaize and WITRON. Delhaize uses one tote footprint and two tote heights; 600 x 400 x 120 mm and 600 x 400 x 240 mm. One advantage of the new foldable and reusable totes is the solid bottom and easy cleaning. This ensures that all hygienic standards can be kept despite intensive use. Moreover, the totes are equipped with an EAN 128 barcode and an UHF RFID tag ensuring 100% tracking and tracing.

Tote warehouse with four independent modulesThe 14,000 m² fresh goods distribution center stores some 2,500 different products like cheese, meat, poultry, convenience food, fruits, vegetables and salad. Storage is high density, with temperatures ranging from +2 - +4 degrees. The tote warehouse has 16 aisles, 32 stacker cranes, and 166,900 tote locations, and is able to pick a daily amount of 295,000 picking units at 48 pick stations. Daily output is as high as 700,000 units when full tote retrievals are considered. The highly dynamic system has a daily output of up to 96,000 store-friendly sorted totes. The logistics center is divided into four identical and independent working modules enabling a high throughput. Each module includes all 2,500 different articles.

The received totes are automatically destacked. They are then checked for temperature, barcode and weight before being stored in the DPS system. Some 70% of the received totes are transported as full totes with single-articles through the distribution center without being picked. These flow-through totes have a throughput time of only a few hours. The remaining 30% of totes are statically and dynamically provided at the pick zones by means of stacker cranes and according to the order structure. The travel distance of the picker who is guided by pick-by-light will be reduced by up to 75%. Goods are directly picked into the order tote. A flexible use of personnel at the individual workstations is possible.

All totes belonging to one order (full totes as well as totes with picked goods) are consolidated in the respective DPS module and stacked automatically on store-friendly dollies. Each dolly receives a label that is clamped during the stacking process so that adhesive labels are no longer required.

A challenging task„Although DPS had already been used for smaller applications within the fresh goods area, a project like Delhaize required many innovative ideas along with expertise from WITRON to provide the customer with a highly effective overall system”, explains WITRON project manager Gerhard Krauß. In order to handle the daily throughput in the system, all articles were repeatedly provided in each of the four modules to ensure that every order can be completely picked in any scenario. Another important factor was the mirrored design of the system with receiving and outbound areas on both sides of the warehouse and the implementation of the required special strategies. A further challenging task was to exactly coordinate the handling of so-called ultra fresh articles i. e. fish with perishable goods with a longer expiration date to avoid spoilage of the very sensitive goods. Strategies and processes have been defined for handling articles that arrive shortly before they are dispatched from the distribution center. These articles need to be transported with the highest priority and extremely short throughput times through all warehouse areas. Another logistical challenge was the direct supply of eight stacking machines that stack the incoming totes in the right sequence from the different modules in a store-friendly way. „With the possibilities provided by the new system, we are able to fulfill the requirements and demands of our customers and gain additional benefits in a highly competitive market”, says Supply Chain Manager Vincent de Hertogh convinced of the effective processes.

Mechanics provided by WITRON subsidiary FASThe mechanic components used in the project both the stacker cranes and tote conveyor system were developed, built and installed by WITRON’s subsidiary FAS.

„FAS designs mechanical elements for WITRON projects according to the principle “design-to-purpose”. That means the mechanics was and will consequently be designed and further developed for the requirements of the WITRON standard modules. This design philosophy provides our customers decisive benefits with regards to performance, availability, life cycle and life cycle costs“, explains WITRON project manager Gerhard Krauß. „And especially for a project like Delhaize – with high throughput, short order throughput times, temperature-controlled areas – it is a must to use a high-quality conveyor system”, continues Gerhard Krauß.

FAS was founded in 1998 and has been part of the WITRON Group since 2005. It produces near Saarbrucken and in Parkstein. FAS has recently expanded its scope from tote and conveyor systems, stacker cranes, COM machines, shuttle vehicles, sequence buffers, stackers and de-stackers, and lifting devices, to now include pallet conveyor and related components. With that in mind, WITRON has already expanded its existing FAS manufacturing area in Parkstein by an additional 18,000 m².

Sustainability and environmental protection – an important factorDuring the construction of Delhaize’s new perishables distribution center, all important environmental and sustainability aspects were considered. Moreover, the roof of the distribution center is equipped with 8,000 m² solar panels. The panels produce an annual output of 450 MWh of electricity. They also use rain water for cooling, which reduces the annual water consumption by 20.000 m³. But the well planned sustainability concept has even more to offer. As one example, 40 percent of the kinetic energy from the stacker cranes is fed back into the network, resulting in an annual electricity savings of 2,000 MWh for Delhaize. Likewise, the newly developed and reusable totes for perishable goods lead to a significant reduction in waste volume. The use of the new totes combined with store-friendly picking has reduced the number of outbound trucks for the same shipping volume, thereby reducing CO² consumption considerably.